4 years ago

MOF derived Mesoporous Nitrogen doped Carbons with high Activity towards Oxygen Reduction

MOF derived Mesoporous Nitrogen doped Carbons with high Activity towards Oxygen Reduction
In order to obtain Platinum-free catalysts for the Oxygen Reduction Reaction (ORR) in Fuel Cells, Nitrogen doped mesoporous carbons were prepared from pyrolysis of three Cobalt metal organic frameworks (MOFs), one linear coordination polymer and one complex. Electron micrographs revealed the presence of pores of different sizes in the samples. Particles resembled polyhedrons, sponges, bars, etc. The catalyst derived from Cobalt 2,3-pyrazinedicarboxylate polymer (700°C) exhibited attractive electrokinetic parameters for the ORR comparable to those of Pt 20% in acidic medium (Tafel slope=82 mV dec−1, exchange current density=10mAcm−1, equilibrium potential=907 mV (vs RHE), half wave potential=720 mV (vs RHE), number of exchanged electrons ca. 4.0, 0.5 M H2SO4). Limiting current and H2O2 yield (< 10%) are similar to those of ZIF-67 derived materials. The half wave potential is shifted to 820 mv (vs RHE) in alkaline medium (0.1 M KOH). The former sample holds a surface area on mesopores which duplicates that of the ZIF-67 700°C. A correlation was found between the current intensity for the ORR and the mesopore area occupied by N (%N x specific area on mesopores). The Cobalt 2,3-pyrazinedicarboxylate derived material (700°C) showed high methanol tolerance compared to Pt 20% (0.05 M methanol, 0.5 M H2SO4), and good ORR durability (after 3000 cycles between 0.25–1.15 V vs RHE, O2 saturated 0.5M H2SO4).

Publisher URL: www.sciencedirect.com/science

DOI: S0013468617316936

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.